diff --git a/mysql-test/main/range.result b/mysql-test/main/range.result index aca500bf038..81098118abd 100644 --- a/mysql-test/main/range.result +++ b/mysql-test/main/range.result @@ -3635,6 +3635,25 @@ SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL; a pk b DROP TABLE t1, t2; SET @@optimizer_switch= @save_optimizer_switch; + +# MDEV-28858 Wrong result with table elimination combined with +# not_null_range_scan +# +CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM; +INSERT INTO t1 VALUES (10,1),(null,2); +CREATE TABLE t2 (pk INT PRIMARY KEY) ENGINE=MyISAM; +INSERT INTO t2 VALUES (1),(2); +SET @save_optimizer_switch= @@optimizer_switch; +SET optimizer_switch= 'not_null_range_scan=on'; +SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b; +b +2 +SET optimizer_switch= 'not_null_range_scan=off'; +SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b; +b +2 +SET @@optimizer_switch=@save_optimizer_switch; +drop table t1,t2; # # End of 10.5 tests # diff --git a/mysql-test/main/range.test b/mysql-test/main/range.test index 6a2e318e732..a785726cb22 100644 --- a/mysql-test/main/range.test +++ b/mysql-test/main/range.test @@ -2492,6 +2492,24 @@ DROP TABLE t1, t2; SET @@optimizer_switch= @save_optimizer_switch; +--echo +--echo # MDEV-28858 Wrong result with table elimination combined with +--echo # not_null_range_scan +--echo # + +CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM; +INSERT INTO t1 VALUES (10,1),(null,2); +CREATE TABLE t2 (pk INT PRIMARY KEY) ENGINE=MyISAM; +INSERT INTO t2 VALUES (1),(2); + +SET @save_optimizer_switch= @@optimizer_switch; +SET optimizer_switch= 'not_null_range_scan=on'; +SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b; +SET optimizer_switch= 'not_null_range_scan=off'; +SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b; +SET @@optimizer_switch=@save_optimizer_switch; +drop table t1,t2; + --echo # --echo # End of 10.5 tests --echo # diff --git a/mysql-test/main/range_mrr_icp.result b/mysql-test/main/range_mrr_icp.result index eb4daf7fbc8..e68af8545cf 100644 --- a/mysql-test/main/range_mrr_icp.result +++ b/mysql-test/main/range_mrr_icp.result @@ -3624,6 +3624,25 @@ SELECT * FROM t1 LEFT JOIN t2 ON a = pk WHERE b >= 0 AND pk IS NULL; a pk b DROP TABLE t1, t2; SET @@optimizer_switch= @save_optimizer_switch; + +# MDEV-28858 Wrong result with table elimination combined with +# not_null_range_scan +# +CREATE TABLE t1 (a INT, b INT) ENGINE=MyISAM; +INSERT INTO t1 VALUES (10,1),(null,2); +CREATE TABLE t2 (pk INT PRIMARY KEY) ENGINE=MyISAM; +INSERT INTO t2 VALUES (1),(2); +SET @save_optimizer_switch= @@optimizer_switch; +SET optimizer_switch= 'not_null_range_scan=on'; +SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b; +b +2 +SET optimizer_switch= 'not_null_range_scan=off'; +SELECT t1.b FROM t1 LEFT JOIN t2 ON t1.a = t2.pk WHERE t1.a IS NULL ORDER BY t1.b; +b +2 +SET @@optimizer_switch=@save_optimizer_switch; +drop table t1,t2; # # End of 10.5 tests # diff --git a/sql/sql_select.cc b/sql/sql_select.cc index c71911f12cd..447ec9c2f73 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -29976,11 +29976,12 @@ bool build_notnull_conds_for_range_scans(JOIN *join, Item *cond, DBUG_ENTER("build_notnull_conds_for_range_scans"); - for (JOIN_TAB *s= join->join_tab + join->const_tables ; + for (JOIN_TAB *s= join->join_tab; s < join->join_tab + join->table_count ; s++) { /* Clear all needed bitmaps to mark found fields */ - if (allowed & s->table->map) + if ((allowed & s->table->map) && + !(s->table->map && join->const_table_map)) bitmap_clear_all(&s->table->tmp_set); } @@ -29995,17 +29996,18 @@ bool build_notnull_conds_for_range_scans(JOIN *join, Item *cond, For each table t from 'allowed' build a conjunction of NOT NULL predicates constructed for all found fields if they are included in some indexes. If the construction of the conjunction succeeds attach the formula to - t->table->notnull_cond. The condition will be used to look for complementary - range scans. + t->table->notnull_cond. The condition will be used to look for + complementary range scans. */ - for (JOIN_TAB *s= join->join_tab + join->const_tables ; + for (JOIN_TAB *s= join->join_tab ; s < join->join_tab + join->table_count ; s++) { TABLE *tab= s->table; List notnull_list; Item *notnull_cond= 0; - if (!(allowed & tab->map)) + if (!(allowed & tab->map) || + (s->table->map && join->const_table_map)) continue; for (Field** field_ptr= tab->field; *field_ptr; field_ptr++) diff --git a/tpool/tpool_generic.cc b/tpool/tpool_generic.cc index dfd780e7ea3..5d99783e8b9 100644 --- a/tpool/tpool_generic.cc +++ b/tpool/tpool_generic.cc @@ -327,21 +327,22 @@ public: int m_period; std::mutex m_mtx; bool m_on; - std::atomic m_running; + std::atomic m_running; void run() { /* In rare cases, multiple callbacks can be scheduled, - e.g with set_time(0,0) in a loop. - We do not allow parallel execution, as user is not prepared. + at the same time,. e.g with set_time(0,0) in a loop. + We do not allow parallel execution, since it is against the expectations. */ - bool expected = false; - if (!m_running.compare_exchange_strong(expected, true)) + if (m_running.fetch_add(1, std::memory_order_acquire) > 0) return; - - m_callback(m_data); - m_running = false; + do + { + m_callback(m_data); + } + while (m_running.fetch_sub(1, std::memory_order_release) != 1); if (m_pool && m_period) {